1. Field of the Invention
The invention relates to a delivery device for delivering oil from a reservoir to a transmission of a motor vehicle.
2. Related Art
Such delivery devices are used in particular in motor vehicles with hybrid drive. In the case of such hybrid drives, the oil pump for providing a supply to a transmission is driven directly by the transmission. When the transmission is at a standstill, the function thereof should be maintained, and therefore the oil pump should remain in operation.
DE 10 2011 084 542 A1 disclosed a drive device for a transmission oil pump. Depending on the design of the components that are movable relative to one another, the oil pump may be a vane-type pump, a gearwheel pump or gerotor pump. The radially inner one of the components that are movable relative to one another is arranged rotationally conjointly on a shaft and can be driven by the direct drive. The pump stage housing is arranged rotationally conjointly on a hollow shaft and can be driven by the electric drive. For this purpose, the pump stage housing is arranged in a recess of the housing of the oil pump, wherein a seal is arranged between housing and pump stage housing. The seal is arranged such that oil is drawn in via an inlet in the housing and via an inlet duct in a control disk, and, after passing the components that are movable relative to one another, and after the associated pressure increase, the oil exits the oil pump via an outlet duct in the opposite control disk and the outlet in the housing. Disadvantages of this are firstly that the screw connection of the control disks to the ring is situated radially outside the components that are movable relative to one another, whereby the impeller part has a large outer diameter. Secondly, the pressure in the impeller part promotes the formation of an axial gap, which has an adverse effect on efficiency.